Dominique Orban

Back

Cahiers du GERAD

78 results — page 3 of 4

, , and

We study X-ray tomograqphic reconstruction using statistical methods. The problem is expressed in cylindrical coordinates, which yield significant computatio...

BibTeX reference
, , , and

Stochastic Dynamic Programming (SDP) is a powerful approach applicable to nonconvex and stochastic stagewise problems. We investigate the impact of the form...

BibTeX reference
, , and

We propose an iterative method named LSLQ for solving linear least-squares problems \(A x \approx b\) of any shape. The method is based on the Golub and K...

BibTeX reference
, , and

For positive definite linear systems (or semidefinite consistent systems), we use Gauss-Radau quadrature to obtain a cheaply computable upper bound on the ...

BibTeX reference
, , and

NLP.py is a programming environment to model continuous optimization problems and to design computational methods in the high-level and powerful Python l...

BibTeX reference

We describe a collection of linear systems generated during the iterations of an interior-point method for convex quadratic optimization. As the iteration...

BibTeX reference
and

Adaptative cubic regularization (ARC) methods for unconstrained optimization compute steps from linear systems with a shifted Hessian in the spirit of the mo...

BibTeX reference
, , , and

In many large engineering design problems, it is not computationally feasible or realistic to store Jacobians or Hessians explicitly. Matrix-free implementat...

BibTeX reference

A preconditioned variant of the Golub and Kahan (1965) bidiagonalization process recently proposed by Arioli (2013) and Arioli and Orban (2013) allows us to ...

BibTeX reference

We propose a generalization of the limited-memory Cholesky factorization of Lin and Moré (1999) to the symmetric indefinite case with special interest in sym...

BibTeX reference
and

Symmetric quasi-definite systems may be interpreted as regularized linear least-squares problem in appropriate metrics and arise from applications such as re...

BibTeX reference
, , and

We describe the most recent evolution of our constrained and unconstrained testing environment and its accompanying SIF decoder. Code-named SIFDecode and CU...

BibTeX reference
, , and

Projected Krylov methods are full-space formulations of Krylov methods that take place in a nullspace. Provided projections into the nullspace can be compute...

BibTeX reference
, , and

Interior-point methods feature prominently among numerical methods for inequality-constrained optimization problems, and involve the need to solve a sequ...

BibTeX reference
, , and

Interior-point methods in semi-definite programming (SDP) require the solution of a sequence of linear systems which are used to derive the search directions...

BibTeX reference
, , and

OPAL is a general-purpose system for modeling and solving algorithm optimization problems. OPAL takes an algorithm as input, and as output it suggests para...

BibTeX reference
and

Implementations of the Simplex method differ only in very specific aspects such as the pivot rule. Similarly, most relaxation methods for mixed-integer ...

BibTeX reference
, , and

The analytic center cutting plane method and its proximal variant are well known techniques for solving convex programming problems. We propose two seq...

BibTeX reference
, , and

We consider a class of infeasible, path-following methods for convex quadratric programming. Our methods are designed to be effective for solving both nonde...

BibTeX reference
and

We propose an interior-point algorithm based on an elastic formulation of the \(\ell_1\)-penalty merit function for mathematical programs with complementar...

BibTeX reference